In related art, technology for segmenting a region of an object such as a person of a detection target, within a photographed image, has been variously developed.
For example, PTL 1 discloses technology that detects moving bodies within an image photographed by a fish-eye lens camera, and respectively segments circumscribed quadrangle regions of each of the detected moving bodies. Further, PTL 2 discloses technology that extracts, based on position information of a partial region extracted with an immediately preceding frame image, and a physical feature amount analyzed from a present frame image, a partial region from each frame image. Further, PTL 3 discloses technology that detects a moving body with a size, an existing time, or a moving speed the largest from among moving bodies extracted from picture data, and segments a region that includes the detected moving body.